The museum said in a statement that pickpocketing was a growing problem despite measures taken last year, including tighter co-operation with the police and temporary bans on people already identified as pickpockets from re-entering the museum. Late last year, the Louvre filed an official complaint to the state prosecutor over visitors falling victim to the thieves.

Many of the thieves are children who get into the museum for free and then start asking people for money.

“Do you speak English?” is their usual opening gambit, and then they surround victims, helping themselves to money and possessions.

And the difficulty in resolving the problem of the 'children of Romanian immigrants (France's Interior Minister)':

“The children are tough and very well organised,” said one member of [Louvre] staff. “They stop at nothing to get what they want, and work in gangs.

“We can only do so much, but arrests are usually impossible because of their young age. If they are kicked out, they return the next day. They are very aggressive towards staff, putting people in danger of attack.”